The present invention provides novel polynucleotides and proteins encoded by such polynucleotides, along with uses for these polynucleotides and proteins, for example in therapeutic, diagnostic and research methods. In particular, the invention relates to a novel human von Willebrand/Thrombospondin-like polypeptides.
Technology aimed at the discovery of protein factors (including e.g., cytokines, such as lymphokines, interferons, CSFs, chemokines, and interleukins) has matured rapidly over the past decade. The now routine hybridization cloning and expression cloning techniques clone novel polynucleotides xe2x80x9cdirectlyxe2x80x9d in the sense that they rely on information directly related to the discovered protein (i.e., partial DNA/amino acid sequence of the protein in the case of hybridization cloning; activity of the protein in the case of expression cloning). More recent xe2x80x9cindirectxe2x80x9d cloning techniques such as signal sequence cloning, which isolates DNA sequences based on the presence of a now well-recognized secretory leader sequence motif, as well as various PCR-based or low stringency hybridization-based cloning techniques, have advanced the state of the art by making available large numbers of DNA/amino acid sequences for proteins that are known to have biological activity, for example, by virtue of their secreted nature in the case of leader sequence cloning, by virtue of their cell or tissue source in the case of PCR-based techniques, or by virtue of structural similarity to other genes of known biological activity.
Identified polynucleotide and polypeptide sequences have numerous applications in, for example, diagnostics, forensics, gene mapping; identification of mutations responsible for genetic disorders or other traits, to assess biodiversity, and to produce many other types of data and products dependent on DNA and amino acid sequences. It is to these polypeptides and the polynucleotides encoding them that the present invention is directed. In particular, this invention is directed to a novel von Willebrand/Thrombospondin-like polypeptides and polynucleotides.
The compositions of the present invention include novel isolated polypeptides, novel isolated polynucleotides encoding such polypeptides, including recombinant DNA molecules, cloned genes or degenerate variants thereof, especially naturally occurring variants such as allelic variants, antisense polynucleotide molecules, and antibodies that specifically recognize one or more epitopes present on such polypeptides, as well as hybridomas producing such antibodies. Specifically, the polynucleotides of the present invention are based on polynucleotide isolated from cDNA library prepared from human fetal brain (Hyseq clone identification number 15258924).
The compositions of the present invention additionally include vectors, including expression vectors, containing the polynucleotides of the invention, cells genetically engineered to contain such polynucleotides and cells genetically engineered to express such polynucleotides.
The isolated polynucleotides of the invention include, but are not limited to, a polynucleotide comprising any one of the nucleotide sequences set forth in the SEQ ID NO: 1-3; a polynucleotide comprising any of the full length protein coding sequences of the SEQ ID NO: 1-3; and a polynucleotide comprising any of the nucleotide sequences of the mature protein coding sequences of the SEQ ID NO: 1-3. The polynucleotides of the present invention also include, but are not limited to, a polynucleotide that hybridizes under stringent hybridization conditions to (a) the complement of any one of the nucleotide sequences set forth in the SEQ ID NO: 1-3; (b) a nucleotide sequence encoding SEQ ID NO: 4-7; a polynucleotide which is an allelic variant of any polynucleotides recited above; a polynucleotide which encodes a species homolog (e.g. orthologs) of any of the proteins recited above; or a polynucleotide that encodes a polypeptide comprising a specific domain or truncation of any of the polypeptides comprising SEQ ID NO: 4-7.
The nucleic acid sequences of the present invention also include the sequence information from the nucleic acid sequences of SEQ ID NO: 1-3. The sequence information can be a segment of any one of SEQ ID NO: 1-3 that uniquely identifies or represents the sequence information of SEQ ID NO: 1-3. One such segment can be a twenty-mer nucleic acid sequence because the probability that a twenty-mer is fully matched in the human genome is 1 in 300. In the human genome, there are three billion base pairs in one set of chromosomes. Because 420 possible twenty-mers exist, there are 300 times more twenty-mers than there are base pairs in a set of human chromosome. Using the same analysis, the probability for a seventeen-mer to be fully matched in the human genome is approximately 1 in 5. When these segments are used in arrays for expression studies, fifteen-mer segment can be used. The probability that the fifteen-mer is fully matched in the expressed sequences is also approximately one in five because expressed sequences comprise less than approximately 5% of the entire genome sequence. Preferably, the nucleic acid fragment or subsequence comprise SEQ ID NO: 1
Similarly, when using a sequence information for detecting a single mismatch, a segment can be a twenty-five mer. The probability that the twenty-five mer would appear in a human genome with a single mismatch is calculated by multiplying the probability for a full match (1÷425) times the increased probability for mismatch at each nucleotide position (3xc3x9725). The probability that an eighteen mer with a single mismatch can be detected in an array for expression studies is approximately one in five. The probability that a twenty-mer with a single mismatch can be detected in a human genome is approximately one in five.
A collection as used in this application can be a collection of only one polynucleotide. The collection of sequence information or unique identifying information of each sequence can be provided on a nucleic acid array. In one embodiment, segments of sequence information is provided on a nucleic acid array to detect the polynucleotide that contains the segment. The array can be designed to detect full-match or mismatch to the polynucleotide that contains the segment. The collection can also be provided in a computer-readable format.
This invention also includes the reverse or direct complement of any of the nucleic acid sequences recited above; cloning or expression vectors containing the nucleic acid sequences; and host cells or organisms transformed with these expression vectors.
Human von Willebrand/Thrombospondin-like (xe2x80x9cThrombospondin-Likexe2x80x9d) polypeptide (SEQ ID NO: 4) is an approximately 235-amino acid protein with a predicted molecular mass of approximately 26 kDa unglycosylated. Protein database searches with the PSI-BLAST algorithm (Altschul S. F. et al., Nucleic Acids Res. vol. 25, pp. 3389-3402, herein incorporated by reference) and eMatrix software indicate that SEQ ID NO: 4 is homologous to african clawed frog thrombospondin 1 precursor and von Willebrand factor. FIG. 1 shows the PSI-BLAST amino acid sequence alignment between SEQ ID NO: 4 (also identified as xe2x80x9cThrombospondin-Likexe2x80x9d) and african clawed frog thrombospondin 1 precursor protein (xe2x80x9cFrog Thrombospondin 1 Precursorxe2x80x9d), indicating that the two sequences share 48% similarity over 58 amino acid residues of SEQ ID NO: 4 and 36% identity over 58 amino acid residues of SEQ ID NO: 4. The sequences of the present invention are expected to have von Willebrand factor or Thrombospondin activity, as defined below.
A predicted approximately eighteen residue signal peptide is encoded from approximately residue 1 to residue 18 of SEQ ID NO: 4. The extracellular portion is useful on its own. This can be confirmed by expression in mammalian cells and sequencing of the cleaved product. The signal peptide region was predicted using the Kyte-Doolittle hydrophobocity prediction algorithm (J. Mol Biol, 157, pp. 105-31 (1982), incorporated herein by reference). One of skill in the art will recognize that the actual cleavage site may be different than that predicted by the computer program.
Using eMatrix software package (Stanford University, Stanford, Calif.) (Wu et al., J. Comp. Biol., vol. 6, pp. 219-235 (1999), herein incorporated by reference), von Willebrand/Thrombospondin-Like is expected to have von Willebrand factor type D domain at residues 124 to 134 of SEQ ID NO: 4 and precursor glycoprotein signal cell signature at residues 101 to 150 of SEQ ID NO: 4. The domains corresponding to SEQ ID NO: 4 are as follows wherein A=Alanine, C=Cysteine, D=Aspartic Acid, E=Glutamic Acid, F=Phenylalanine, G=Glycine, H=Histidine, I=Isoleucine, K=Lysine, L=Leucine, M=Methionine, N =Asparagine, P=Proline, Q=Glutamine, R=Arginine, S=Serine, T=Threonine, V=Valine, W=Tryptophan, Y=Tyrosine:
von Willebrand factor type D domain (CWCEDGKVTC designated as SEQ ID NO: 6): p-value of 1.918e-09, PF00094C (identification number correlating to signature), located at residues 124-134 of SEQ ID NO: 4; and
Precursor glycoprotein signal cell signature (SPCWHLGAMHESRSRWTEPGCSQCWCEDGKVTCEKVRCEAACSHPIPSR designated as SEQ ID NO: 7): p-value of 9.057e-09, PD02576A (identification number correlating to signature), located at residues 101 to 150 of SEQ ID NO: 4.
Precursor glycoprotein signal cell signature and von Willebrand factor type D domain situated in the same region of SEQ ID NO: 4 indicates that SEQ ID NO: 4 may be involved in the clot formation process.
Von Willebrand/Thrombospondin-like polypeptide has characteristics of members of the thrombospondin family as well as of von Willebrand factors. Members of the thrombospondin family are able to inhibit angiogenesis, or new blood vessel formation that aids tumor growth. (See, e.g., Volpert et al., Biochem Biophys Res Commun, vol 217, pp. 326-32 (1995); Tokunaga et al., Br. J. Cancer, vol 79, pp. 354-9 (1999), both incorporated herein by reference). Researchers have found that down regulation of thrombospondin may be associated with Kaposi""s sarcoma, a neoplasm often associated with iatrogenic and aquired immunosuppression. (Taraboletti et al., J. Pathol. vol. 188, pp. 76-81 (1999), incorporated herein by reference). Other researchers have found that thrombospondin-1 has a carboxy-terminal cell-binding domain that is essential for the adhesion of sickle red blood cells under flow conditions. (Hillery et al., Blood, vol. 94, pp. 302-309 (1999), incorporated herein by reference).
The polypeptides and polynucleotides of the invention can be utilized, for example, as part of methods for the prevention and/or treatment of disorders involving abnormal bleeding, von Willebrand disease, haemophilia, angiogenesis, sickle cell anemia, cancer, and AIDS. von Willebrand disease is a common hereditary bleeding disease affecting approximately 1% of the United States population. It is caused by a deficiency or defect in a plasma protein critical to blood clotting.
The isolated polypeptides of the invention include, but are not limited to, a polypeptide comprising SEQ ID NO: 4-7; or the corresponding full length or mature protein. Polypeptides of the invention also include polypeptides with biological activity that are encoded by (a) any of the polynucleotides having a nucleotide sequence set forth in the SEQ ID NO: 1-3; or (b) polynucleotides that hybridize to the complement of the polynucleotides of (a) under stringent hybridization conditions. Biologically or immunologically active variants of any of the protein sequences listed as SEQ ID NO: 4-7 and xe2x80x9csubstantial equivalentsxe2x80x9d thereof (e.g., with at least about 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% amino acid sequence identity) that preferably retain biological activity are also contemplated. The polypeptides of the invention may be wholly or partially chemically synthesized but are preferably produced by recombinant means using the genetically engineered cells (e.g. host cells) of the invention.
The invention also provides compositions comprising a polypeptide of the invention. Polypeptide compositions of the invention may further comprise an acceptable carrier, such as a hydrophilic, e.g., pharmaceutically acceptable, carrier.
The invention also provides host cells transformed or transfected with a polynucleotide of the invention.
The invention also relates to methods for producing a polypeptide of the invention comprising growing a culture of the host cells of the invention in a suitable culture medium under conditions permitting expression of the desired polypeptide, and purifying the protein from the culture or from the host cells. Preferred embodiments include those in which the protein produced by such process is a mature form of the protein.
Polynucleotides according to the invention have numerous applications in a variety of techniques known to those skilled in the art of molecular biology. These techniques include use as hybridization probes, use as oligomers, or primers, for PCR, use in an array, use in computer-readable media, use for chromosome and gene mapping, use in the recombinant production of protein, and use in generation of anti-sense DNA or RNA, their chemical analogs and the like. For example, when the expression of an mRNA is largely restricted to a particular cell or tissue type, polynucleotides of the invention can be used as hybridization probes to detect the presence of the particular cell or tissue mRNA in a sample using, e.g., in situ hybridization.
In other exemplary embodiments, the polynucleotides are used in diagnostics as expressed sequence tags for identifying expressed genes or, as well known in the art and exemplified by Vollrath et al., Science 258:52-59 (1992), as expressed sequence tags for physical mapping of the human genome.
A polynucleotide according to the invention can be joined to any of a variety of other nucleotide sequences by well-established recombinant DNA techniques (see Sambrook, J., et al. (1989) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, N.Y.). Useful nucleotide sequences for joining to polypeptides include an assortment of vectors, e.g., plasmids, cosmids, lambda phage derivatives, phagemids, and the like, that are well known in the art. Accordingly, the invention also provides a vector including a polynucleotide of the invention and a host cell containing the polynucleotide. In general, the vector contains an origin of replication functional in at least one organism, convenient restriction endonuclease sites, and a selectable marker for the host cell. Vectors according to the invention include expression vectors, replication vectors, probe generation vectors, and sequencing vectors. A host cell according to the invention can be a prokaryotic or eukaryotic cell and can be a unicellular organism or part of a multicellular organism.
The polypeptides according to the invention can be used in a variety of conventional procedures and methods that are currently applied to other proteins. For example, a polypeptide of the invention can be used to generate an antibody that specifically binds the polypeptide. Such antibodies, particularly monoclonal antibodies, are useful for detecting or quantitating the polypeptide in tissue. The polypeptides of the invention can also be used as molecular weight markers, and as a food supplement.
Methods are also provided for preventing, treating, or ameliorating a medical condition which comprises the step of administering to a mammalian subject a therapeutically effective amount of a composition comprising a protein of the present invention and a pharmaceutically acceptable carrier.
In particular, the polypeptides and polynucleotides of the invention can be utilized, for example, as part of methods for the prevention and/or treatment of disorders involving aberrant protein expression or biological activity.
The methods of the invention also provides methods for the treatment of disorders as recited herein which may involve the administration of the polynucleotides or polypeptides of the invention to individuals exhibiting symptoms or tendencies related to disorders as recited herein. In addition, the invention encompasses methods for treating diseases or disorders as recited herein comprising the step of administering compounds and other substances that modulate the overall activity of the target gene products. Compounds and other substances can effect such modulation either on the level of target gene/protein expression or target protein activity. Specifically, methods are provided for preventing, treating or ameliorating a medical condition, including neurological diseases, which comprises administering to a mammalian subject, including but not limited to humans, a therapeutically effective amount of a composition comprising a polypeptide of the invention or a therapeutically effective amount of a composition comprising a binding partner of (e.g., antibody specifically reactive for) von Willebrand/Thrombospondin-like polypeptides of the invention. The mechanics of the particular condition or pathology will dictate whether the polypeptides of the invention or binding partners (or inhibitors) of these would be beneficial to the individual in need of treatment.
According to this method, polypeptides of the invention can be administered to produce an in vitro or in vivo inhibition of cellular function. A polypeptide of the invention can be administered in vivo as a von Willebrand/Thrombospondin-like protein alone or as an adjunct to other therapies. Conversely, protein or other active ingredient of the present invention may be included in formulations of the particular clotting factor, cytokine, lymphokine, other hematopoietic factor, thrombolytic or anti-thrombotic factor, or anti-inflammatory agent to minimize side effects of the clotting factor, cytokine, lymphokine, other hematopoietic factor, thrombolytic or anti-thrombotic factor, or anti-inflammatory agent.
The invention further provides methods for manufacturing medicaments useful in the above described methods.
The present invention further relates to methods for detecting the presence of the polynucleotides or polypeptides of the invention in a sample (e.g., tissue or sample). Such methods can, for example, be utilized as part of prognostic and diagnostic evaluation of disorders as recited herein and for the identification of subjects exhibiting a predisposition to such conditions. The invention also provides kits comprising polynucleotide probes and/or monoclonal antibodies, and optionally quantitative standards, for carrying out methods of the invention. Furthermore, the invention provides methods for evaluating the efficacy of drugs, and monitoring the progress of patients, involved in clinical trials for the treatment of disorders as recited above.
The invention also provides methods for the identification of compounds that modulate (i.e., increase or decrease) the expression or activity of the polynucleotides and/or polypeptides of the invention. Such methods can be utilized, for example, for the identification of compounds that can ameliorate symptoms of disorders as recited herein. Such methods can include, but are not limited to, assays for identifying compounds and other substances that interact with (e.g., bind to) the polypeptides of the invention.